The present disclosure relates to an image pickup lens suitable for a compact image pickup unit that uses an image pickup device such as a CCD (Charge Coupled Device) and a CMOS (Complementary Metal Oxide Semiconductor). Examples of such a compact image pickup unit may include a digital still camera, a mobile phone with a camera, etc. The present disclosure also relates to an image pickup unit that uses such an image pickup lens.
A mobile phone with a camera, a digital still camera, and the like that use a solid-state image pickup device such as a CCD and a CMOS are known. There has been a demand for further reducing size of such an image pickup unit, and also, a compact lens having a short total optical length is demanded as a lens for shooting to be mounted thereon.
Moreover, recently, also in the compact image pickup unit such as the mobile phone with a camera, pixel density of the image pickup device has been increased while a size thereof has been reduced, and a model provided with an image pickup device having high pixel density equivalent to that of a digital still camera has been widely used. Accordingly, high lens performance suitable for such a high-pixel-density solid-state image pickup unit has been demanded in the image pickup lens mounted on the image pickup unit.
Moreover, a lens having a smaller aperture Fno has been demanded in order to achieve increase in shutter speed while preventing degradation in image quality caused by noise during shooting in a dark place. In such compact and high-performance image pickup lens, an image pickup lens having a configuration with five or more lenses is necessary. For example, Japanese Unexamined Patent Application Publication Nos. 2009-294527 (JP2009-294527A), 2009-294528 (JP2009-294528A), and 2010-262269 (JP2010-262269A), and International Publication No. 2010/024198 (WO2010/024198) disclose an image pickup lens having a five-lens configuration.